Michelle Mello Answers Questions About the Federal Rollout of the Coronavirus Test

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Controversies over the lack of diagnostic testing for the COVID-19 virus have dominated U.S headlines for weeks. Technical challenges with the first test developed by the Centers for Disease Control and Prevention (CDC) left the nation with minimal diagnostic capacity during the first few weeks of the epidemic, according to a new paper published today in the Journal of the American Medical Association by Michelle Mello, a professor of medicine at Stanford Health Policy and professor of law at Stanford Law School.

On February 29, the Food and Drug Administration (FDA) began allowing high-complexity labs across the country to use tests they developed in-house. On March 5, the Stanford Clinical Virology Lab deployed its own test for patients at Stanford Health Care and Stanford Children’s Health.

We asked Mello to answer some questions about the federal rollout of diagnostic testing.


You write that in the early stages, COVID-19 “spread beyond the nation’s ability to detect it.” Is there anything the U.S. government could or should have done weeks ago to get out ahead of the spread?

Adopting broader testing criteria and allowing use of a wider range of tests would have been helpful in identifying the first U.S. cases and containing the spread. Manufacturing problems like the one that arose with CDC’s test are always a risk, but the fact that CDC put all its eggs in that one basket made the manufacturing snafu highly consequential.

Also, the public messaging from Washington about the seriousness of the problem has been neither consistent nor accurate, and I worry it may have led Americans to take fewer steps to prevent community transmission than we should have. Containment was not “pretty close to airtight.” A vaccine was never going to be ready in “three to four months,” as the Trump administration claimed. The case fatality rate is not “way under 1 percent.” Part of the problem here is that as the stock market continues to plunge, the president and the task force he appointed appear to be more concerned about calming investors than stopping the virus.

We seem to be between a rock and a hard place: You write that remedying gaps in testing is imperative, yet “more testing is not always better.” How do we determine the happy middle ground?

First, the testing criteria have to be calibrated to our actual testing capacity. You can’t announce that any American who wants a coronavirus test can get one and then, within hours, announce that there aren’t enough test kits to make that possible. High priorities for testing include patients with serious, unexplained respiratory illness and contacts of known cases. From there, testing can be expanded, beginning with other high-risk groups, as capacity permits.

Second, we should consider unintended side effects of mass testing. The problem with this virus is that it doesn’t have signature symptoms. It looks like the common cold or the flu. If everyone with a cough or fever, or who has been around someone with a cough or fever, shows up in their doctor’s office demanding a test, it will quickly overwhelm care facilities that should be focusing on patients with a higher likelihood of being infected or and those who are infected and are seriously ill. It may also work against the social distancing measures that public health officials are trying to encourage, because crowded waiting rooms may spread the virus.

The CDC announced Monday it now has the testing capacity in 78 state and local public health labs across 50 states to test for the virus. There are now 75,000 lab kits cumulatively to test for COVID-19 with more coming on board by mid-March. But is there anything we could have done to roll this out earlier?

The alternative would have been to allow laboratories to deploy their own tests from the beginning, using the primers and protocols made publicly available by the World Health Organization. That’s what other countries have done. RT-PCR is a mature technology and high-complexity labs around the country are well-qualified to conduct this type of testing.

There is a public health argument for not going that route: perhaps those labs wouldn’t have done as good a job as CDC’s own lab and the state labs that it handpicked early in the outbreak. What if there were erroneous test results? We could miss cases, or we could put people into isolation, with huge social consequences, based on false-positive results. There is also a worry that some labs aren’t consistent about reporting positive test results to CDC, and underreporting could compromise disease surveillance efforts.

The counterargument is that high-complexity labs have that certification for a reason—they’re good at what they do. And of course, surveillance is also compromised when you miss cases because you don’t test.

You write in your paper that testing for COVID-19 “highlights a controversial area of public policy—the regulation of laboratory-developed tests—in which there has long been tension between the goals of access and quality.” Who should be in charge of regulating these tests?

Laboratory-developed tests are largely unregulated outside of emergencies. The FDA proposed draft guidance in 2014 that, if implemented, would have required labs to make certain showings to FDA about tests they developed in-house, with the particular evidence calibrated to the risks involved in having a wrong test result. Contrary to President Trump’s claim that an Obama-era policy constrained coronavirus testing, the guidance did not relate to emergency situations. During declared emergencies, another statute and set of regulations apply, and the FDA has broad discretion to allow or disallow use of novel diagnostics and therapies as emergency countermeasures.

As a general matter, it makes good sense to require labs to submit evidence that their in-house tests work. It’s odd that laboratory-developed tests are carved out of requirements that apply to other kinds of medical devices. It’s also sensible that our legal framework allows FDA’s regular rules to be relaxed during emergencies so we can tailor our response to the difficult and changing circumstances.

You write that diagnostic testing is critical to an effective response to the novel coronavirus. What sort of policies and guidelines should be put into place to prevent such a sluggish rollout during an emerging epidemic the next time one comes around?

The legal framework for an effective emergency response is in place. Because giving agency heads the discretion to act as potentially unforeseeable circumstances require is a linchpin of this legal framework, it only works if leaders make smart choices. Every emergency is different, and there is a danger of Monday-morning quarterbacking. But we should learn from every misstep we make, and I think the lesson here is to make better use of already developed networks of highly qualified labs to make sure we have adequate testing capacity to isolate cases and trace their contacts very early in an outbreak.

What are some innovative approaches we could be taking to speed up testing for those who really need it?

The South Koreans have set up drive-through testing stations in parking lots to avoid concentrating crowds of people indoors. Of course, that requires that you have plenty of test kits, which we don’t yet – but we should also be thinking about creative ways to address the epidemic. For example, how could video calls be used to monitor the health of people confined at home after being exposed to the virus? How can social media be used to connect neighbors to help one another when some are isolated at home? Hopefully we can find new ways for technology to bring us together when pathogens drive us apart.